50=-16t^2+64t+3

Solution for 50=-16t^2+64t+3 equation:

50=-16t^2+64t+3

We move all terms to the left:

50-(-16t^2+64t+3)=0

We get rid of parentheses

16t^2-64t-3+50=0

We add all the numbers together, and all the variables

16t^2-64t+47=0

a = 16; b = -64; c = +47;
Δ = b2-4ac
Δ = -642-4·16·47
Δ = 1088
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1088}=\sqrt{64*17}=\sqrt{64}*\sqrt{17}=8\sqrt{17}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-64)-8\sqrt{17}}{2*16}=\frac{64-8\sqrt{17}}{32}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-64)+8\sqrt{17}}{2*16}=\frac{64+8\sqrt{17}}{32}
$